[SYCL] Disable fallback assert by default

sycl/doc/PreprocessorMacros.md

@@ -38,16 +38,18 @@ This file describes macros that have effect on SYCL compiler and run-time.
 
   Disables a message which warns about unsupported C++ version.
 
-- **SYCL_DISABLE_FALLBACK_ASSERT**
-
-  Defining this macro eliminates some overhead that is associated with
-  submitting kernels that call `assert()`. When this macro is defined, the logic
-  for detecting assertion failures in kernels is disabled, so a failed assert
-  will not cause a message to be printed and will not cause the program to
-  abort. However, this macro only affects kernels that are submitted to devices
-  that do **not** have native support for `assert()` because devices with native
-  support do not impose any extra overhead. One can check to see if a device has
-  native support for `assert()` via `aspect::ext_oneapi_native_assert`.
+- **SYCL_ENABLE_FALLBACK_ASSERT**
+
+  Defining this macro enables the fallback assert feature even on devices
+  without native support. Be aware that this will add some overhead that is
+  associated with submitting kernels that call `assert()`. When this macro is
+  not defined, the logic for detecting assertion failures in kernels is
+  disabled, so a failed assert will not cause a message to be printed and will
+  not cause the program to abort. Some devices have native support for
+  assertions. The logic for detecting assertion failures is always enabled on
+  these devices regardless of whether this macro is defined because that logic
+  does not add any extra overhead. One can check to see if a device has native
+  support for `assert()` via `aspect::ext_oneapi_native_assert`.
 
 ## Version macros
 

sycl/include/CL/sycl/queue.hpp

@@ -63,7 +63,7 @@
 
 // Helper macro to identify if fallback assert is needed
 // FIXME remove __NVPTX__ condition once devicelib supports CUDA
-#if !defined(SYCL_DISABLE_FALLBACK_ASSERT) && !defined(__NVPTX__)
+#if defined(SYCL_ENABLE_FALLBACK_ASSERT) && !defined(__NVPTX__)
 #define __SYCL_USE_FALLBACK_ASSERT 1
 #else
 #define __SYCL_USE_FALLBACK_ASSERT 0

sycl/unittests/assert/assert.cpp

@@ -18,6 +18,7 @@
  * pipe.
  */
 
+#define SYCL_ENABLE_FALLBACK_ASSERT 1
 #include <CL/sycl.hpp>
 
 #include <helpers/CommonRedefinitions.hpp>